Was wondering if anyone has a fuel pressure regulator right before their carb? Holley 750 on a 350 bored 30. What psi are you running? had it at 6, runs ok, but lack of power. had it at 12.5 and just drank the gas, had bad timing so never did try to crank on it with more pressure so i'm wondering what psi to set it at on the street for mpg, and what pressure to set it at at the track for hp and mph?

Thanx in advance
The Cable Guy

 

Keep the pressure between 4 and 7 psi.

The reason it ran rich at 12.5 is the needles and seats couldn't shut off the flow when the bowls were full.

All fuel pressure does is keep the bowls full. You don't "tune" with fuel pressure on a carb.

 

I know you don't tune with it, but i didn't know if adding more pressure on the track would benefit any... never dealt with a pressure regulator so still new on that one. But thank you for the help, i appreciate it!

 

I'm running a 781 (I think thats what it is) holley street avenger in a 71 chevy truck, and i used one of those chrome holley pressure regulators for use with those blue top holley electric pumps. I set the regulator to 6 psi before i set the bowls, and the truck runs like a rapped ape. Five7kid is absolutly right. 4-7 psi is perfect, more towards 6-6.5 if you have a thirsty motor. Be very careful not to run those 12.5 psi pressures, the bowl vents have a nasty habit of overflowing if the needles don't seat. The last thing you want to do is roast marshmellows at the racetrack. Feel free to stab holes, but I think the best thing to do is find the carb number for what you got (normally on the choke riser housing on the right top corner, ish), and search for an installation manual for that carb. It will help you tune your carb for best overall performance, which you can use as a baseline for other "power" tuning in the future.

 

see, this is why i post on here and don't feel stupid doing it. Thank you to everyone for your help on this one... really do appreciate the help!

pssst.... now go find my other posts and figure those out too... LOL

Thanx everybody!

 

Many who come from the EFI world don't, and I couldn't tell from your original post whether or not you did.